Effect of acid-base properties on copper catalysts for hydrogenation of carbon dioxide

Abstract

Acidic or basic components as co-catalysts were added to the Cu-based catalysts for hydrogenation of C02. Effects of acid-base properties on the catalytic activity and methanol selectivity are discussed.

Recent Advances in Carbon Dioxide Hydrogenation to Methanol via Heterogeneous Catalysis

“…The acid sites can foster CO 2 adsorption, while the basic sites facilitate the hydrogenation of intermediates. 83 TiO 2 is one of the most studied modifier to decorate the catalyst surface and tune metal-support interaction. This is because (i) Ti IV is a Lewis acid, (ii) the reducibility of TiO 2 can result in the formation of oxygen vacancies accompanied with partial reduction of Ti IV to Ti III , and (iii) partial coverage of Cu surface atoms at the periphery of TiO x can lead to SMSI.…”

“…The type of promoters/modifiers is diverse, and the commonly used metals are alkali and alkaline-earth metals, rare-earth metals, transition metals, and main group metals. , Their functionalities for CH 3 OH synthesis include (i) improving Cu dispersion and surface area, (ii) adjusting the adsorption properties and the surface H/C ratios, (iii) tuning interaction between Cu and metal oxide for H 2 spillover, and (iv) tailoring the support materials with desired single-metal sites at the periphery of Cu NPs. Some nonmetal materials such as graphene oxide and C 3 N 4 are also promising as modifiers …”

“…Transition metal oxides with amphoteric properties, such as TiO 2 and ZrO 2 , are popular candidates as both support and additive. The acid sites can foster CO 2 adsorption, while the basic sites facilitate the hydrogenation of intermediates . TiO 2 is one of the most studied modifier to decorate the catalyst surface and tune metal-support interaction.…”

Effect of TiO2, ZrO2, and TiO2–ZrO2 on the performance of CuO–ZnO catalyst for CO2 hydrogenation to methanol

“…Tagawa et al [13] investigated the effects of acidity and basicity of support on performance of Cu-based catalysts and found that amphoteric supports (Al 2 O 3 , TiO 2 , ZrO 2 ) showed high activities. Among them, TiO 2 support can suppress effectively the reverse water gas shift reaction, hence showing the highest methanol selectivity [25]. On the other hand, A c c e p t e d M a n u s c r i p t (TOF) among three catalysts (Cu/Al 2 O 3 , Cu/SiO 2 , and Cu/TiO 2 ).…”

Catalytic valorization of CO2 by hydrogenation: current status and future trends

“…There are plenty of promoters/modifiers for Cu catalysts, but commonly alkali and alkalineearth metals, [133] rare earth metals, [134] transition metals [135] and main group metals [136] are used. Their performance in CO2 hydrogenation to methanol helps to improve the Cu dispersion surface area, conveys support in the adjustment of the adsorption properties and the surface H/C ratios, assist in the interaction between Cu and metal oxide for H2 spillover and adjust the support material with desired single metal sites at the periphery of Cu NP.…”